SEOUL, Nov. 28 (Yonhap) -- South Korea's top nuclear envoy will visit China this week to discuss the situation of the Korean Peninsula and North Korean issues, Seoul's foreign ministry said Wednesday, amid reports the communist country appears to prepare for another ballistic missile test.

According to military sources in Seoul, North Korea may fire a long-range missile in the next two months. Images taken by U.S. satellites also showed a marked increase in activity at a North Korean missile launch site at its northwestern tip, suggesting the country is stepping up preparations for a test.

Lim Sung-nam, Seoul's chief negotiator to the six-party talks aimed at ending Pyongyang's nuclear ambitions, will hold talks with his Chinese counterpart Wu Dawei and other Beijing officials during his two-day trip from Thursday, according to the ministry.

Lim last visited Beijing in September, during which the two sides said they are "keeping a close watch on the North's new light-water atomic reactor," the official said on the condition of anonymity.

During the scheduled talks, the envoys plan to "assess the current situation of the Korean Peninsula and exchange views on China's policy to North Korea under the new leadership," the foreign ministry said.

Xi Jinping assumed the posts of China's Communist Party leader and head of the military commission earlier this month.

The speculation that the North is in the final stage of preparations for a launch will also be on the agenda, according to sources here, while the ministry said the trip "is part of the two countries' regular policy coordination and cooperation on North Korean issues."

The six-party talks, which involve the two Koreas, the United States, China, Russia and Japan, have been dormant since late 2008.